You really don't need to be so afraid of going into Gamestop. I just went today, 25 year old male. Not a neckbeard. Clean shaven in a band shirt type of look.
Anyhow, there was a cute blonde tomboy, being chatted up by some hipster that wanted information about working there. Infinitely more creepy than any of you think you are.
Just go in, if they don't have the DS set up, ask them politely if you can. Get your Shiny then walk out. Easy as that.